1. Technical Field
The present invention relates to the technical field of a driving system for driving an electro-optic device, such as a liquid crystal device, an electro-optic device equipped with such a driving system, and an electronic device equipped with such an electro-optic device.
2. Related Art
An example of electro-optic devices of this type is a liquid crystal device in which liquid crystal, which is an example of electro-optic materials, is sandwiched between a pair of a device substrate and a counter substrate. A plurality of pixels are arrayed in a pixel area on the device substrate in such a manner that a plurality of pixel sections each including a pixel electrode are arrayed flat in a matrix form so as to correspond to the intersections of scanning lines and data lines. Each of the pixel sections has, as a pixel switching element, for example, a thin-film transistor (hereinafter referred to as a TFT). When the electro-optic device is driven, scanning signals are supplied to the pixel sections through the scanning lines, so that the pixel switching elements are turned on. Then image signals are supplied to the pixel electrodes through the data lines via the pixel switching elements. Typically, a common electrode (or a counter electrode) corresponding to the plurality of pixel electrodes is formed in a solid manner over the plurality of pixel sections across the whole pixel area. When the liquid crystal device is driven, a voltage based on the potential difference between the pixel electrodes and the common electrode is applied to the liquid crystal. Thus, the orientation and order of the liquid crystal are controlled to allow image display.
Low power consumption is earnestly required for liquid crystal devices because of the characteristics, features, and purposes of an electronic device applied. On the other hand, data lines are driven at a high frequency, and a voltage amplitude as high as 10 volts or more is generally necessary to drive liquid crystal, so that data lines are generally supplied with image signals having a high voltage amplitude.
To meet such a request for low power consumption, JP-A-2002-196358 discloses a liquid crystal device that achieves low power consumption by shifting the potential of one end of a storage capacitor element (for example, a capacitor) connected in parallel to liquid crystal to a high level or a low level depending on whether the potential of an image signal supplied to the data line is for positive-polarity writing or negative-polarity writing to thereby decrease the voltage amplitude of the image signal supplied to the data line. JP-A-2006-313319 discloses a liquid crystal device that achieves further low power consumption by, in addition to the structure disclosed in JP-A-2002-196358, bringing the potential of a data line to a voltage corresponding to the same writing polarity among one group of scanning lines to thereby decrease the frequency of the inversion signal of the data line.
However, there is a still further request for lower power consumption.